Emergence of Resistance in Klebsiella aerogenes to Piperacillin-Tazobactam and Ceftriaxone.

We examined the effects of piperacillin-tazobactam (TZP) concentration and bacterial inoculum on in vitro killing and the emergence of resistance in Klebsiella aerogenes The MICs for 15 clinical respiratory isolates were determined by broth microdilution for TZP and by Etest for ceftriaxone (CRO) and cefepime (FEP). The presence of resistance in TZP-susceptible isolates (n = 10) was determined by serial passes over increasing concentrations of TZP-containing and CRO-containing agar plates. Isolates with growth on TZP 16/4-µg/ml and CRO 8-µg/ml plates (n = 5) were tested in high-inoculum (HI; 7.0 log10 CFU/ml) and low-inoculum (LI; 5.0 log10 CFU/ml) time-kill studies. Antibiotic concentrations were selected to approximate TZP 3.375 g every 8 h (q8h) via a 4-h prolonged-infusion free peak concentration (40 µg/ml [TZP40]), peak epithelial lining fluid (ELF) concentrations, and average AUC0-24 values for TZP (20 µg/ml [TZP20] and 10 µg/ml [TZP10], respectively), the ELF FEP concentration (14 µg/ml), and the average AUC0-24 CRO concentration (6 µg/ml). For HI, FEP exposure significantly reduced 24-h inocula against all comparators (P ≤ 0.05) with a reduction of 4.93 ± 0.64 log10 CFU/ml. Exposure to TZP40, TZP20, and TZP10 reduced inocula by 0.81 ± 0.43, 0.21 ± 0.18, and 0.05 ± 0.16 log10 CFU/ml, respectively. CRO-exposed isolates demonstrated an increase of 0.42 ± 0.39 log10 CFU/ml compared to the starting inocula, with four of five CRO-exposed isolates demonstrating TZP-nonsusceptibility. At LI after 24 h of exposure to TZP20 and TZP10, the starting inoculum decreased by averages of 2.24 ± 1.98 and 2.91 ± 0.50 log10 CFU/ml, respectively. TZP demonstrated significant inoculum-dependent killing, warranting dose optimization studies.

Defatted microalgae (Nannochloropsis sp.) from biorefinery as a potential feed protein source to replace fishmeal in European sea bass diets.

The present work focuses on the use of defatted biomass of the microalga Nannochloropsis sp. from the biodiesel industry, as a partial substitute of fish meal (FM) in diets for European sea bass. The effects of increasing inclusion levels of microalgal meal on growth performance, body composition, nutrient utilization, gut morphology, and innate immunity were evaluated after 93 days. A reference alga-free diet was the control (CTRL) diet, and the three experimental diets contained 5 (MA5), 10 (MA10), and 15% (MA15) of the microalgal meal. The microalga-rich diets were supplemented with DL-methionine to assure sea bass dietary requirement. Overall, nutrient apparent digestibilities (ADCs) of the diets were not altered by the microalgal inclusion, but energy ADC was highest in fish fed the CTRL diet (90% vs 88%). At the end of the trial, fish growth performance was similar among dietary treatments (DGI of 1.0), but fish fed MA10 had a significantly higher feed conversion ratio than those fed CTRL and MA5. Final whole body composition and nutrient gain of fish fed the different diets were similar. No significant differences were detected in gut morphology among treatments. Innate immune parameters (lysozyme, alternative complement pathway-ACH50, and peroxidase) were examined, and ACH50 of the fish fed MA15 was significantly lower than those fed MA10, suggesting a dose-dependent stimulation of the innate immune response. The present results indicate that defatted microalgal meal can replace fishmeal in European sea bass diets-at inclusion levels of up to 15%-contributing to a circular economy approach.

Assessment of chromosomal damage induced by a deltamethrin-based insecticide in fish (Anguilla anguilla L.) - a follow-up study upon exposure and post-exposure periods.

The pyrethroid insecticide Decis®, containing deltamethrin as active ingredient, is among the most popular broad-spectrum biocides, with wide application in agriculture and home pest control. The occurrence of deltamethrin in the aquatic environment is well-established, but the possible genotoxic effects of Decis® in non-target organisms, namely fish, remain unknown. Hence, this work aimed to evaluate the cytogenetic damaging potential of Decis® in European eel (Anguilla anguilla L.), adopting the erythrocytic nuclear abnormalities (ENAs) assay. In addition, it was intended to investigate the damage progression in the post-exposure period. The frequency of immature erythrocytes (IE) was also determined to provide indirect information on the erythrocyte catabolism and erythropoiesis rate. Fish were exposed to 17.5 and 35 µg L(-1) of Decis® (equivalent to 0.05 and 0.1 µg L(-1) of deltamethrin, respectively) during 1 and 3 days. Thereafter, fish were transferred to clean water and kept for 1, 7 and 14 days. The results demonstrated a clear potential to induce chromosomal damage following 3 days exposure, depicted in an ENA frequency increase for both Decis® concentrations. The transient nature of this cytogenetic damage was also demonstrated, as ENA frequency returned to the control level 1 and 7 days after cessation of the exposure, respectively for the higher and the lower Decis® concentration. Moreover, this response pattern suggested a rapid metabolization and elimination of the formulation constituents by A. anguilla, combined with an increased erythrocyte turnover in fish exposed to the higher Decis® concentration, as pointed out by the IE frequency rise. Overall, the demonstrated genotoxic properties of Decis® pointed out increased risk factors to fish exposed to this insecticide.

Disulfiram: A Repurposed Drug in Preclinical and Clinical Development for the Treatment of Infectious Diseases.

This article reviews preclinical and clinical studies on the repurposed use of disulfiram (Antabuse) as an antimicrobial agent. Preclinical research covered on the alcohol sobriety aid includes uses as an anti-MRSA agent, a carbapenamase inhibitor, antifungal drug for candidiasis, and treatment for parasitic diseases due to protozoa (e.g., giardiasis, leishmaniasis, malaria) and helminthes (e.g., schistosomiasis, trichuriasis). Past, current, and pending clinical studies on disulfiram as a post-Lyme disease syndrome (PTLDS) therapy, an HIV latency reversal agent, and intervention for COVID-19 infections are also reviewed..

Towards a comprehensive sustainability methodology to assess anthropogenic impacts on ecosystems: Review of the integration of Life Cycle Assessment, Environmental Risk Assessment and Ecosystem Services Assessment.

Nowadays, a variety of methodologies are available to assess local, regional and global impacts of human activities on ecosystems, which include Life Cycle Assessment (LCA), Environmental Risk Assessment (ERA) and Ecosystem Services Assessment (ESA). However, none can individually assess both the positive and negative impacts of human activities at different geographical scales in a comprehensive manner. In order to overcome the shortcomings of each methodology and develop more holistic assessments, the integration of these methodologies is essential. Several studies have attempted to integrate these methodologies either conceptually or through applied case studies. To understand why, how and to what extent these methodologies have been integrated, a total of 110 relevant publications were reviewed. The analysis of the case studies showed that the integration can occur at different positions along the cause-effect chain and from this, a classification scheme was proposed to characterize the different integration approaches. Three categories of integration are distinguished: post-analysis, integration through the combination of results, and integration through the complementation of a driving method. The literature review highlights that the most recurrent type of integration is the latter. While the integration through the complementation of a driving method is more realistic and accurate compared to the other two categories, its development is more complex and a higher data requirement could be needed. In addition to this, there is always the risk of double-counting for all the approaches. None of the integration approaches can be categorized as a full integration, but this is not necessarily needed to have a comprehensive assessment. The most essential aspect is to select the appropriate components from each methodology that can cover both the environmental and socioeconomic costs and benefits of human activities on the ecosystems.

Testing the hydroponic performance of the edible halophyte Halimione portulacoides, a potential extractive species for coastal Integrated Multi-Trophic Aquaculture.

Sea purslane Halimione portulacoides (L.) Aellen is a candidate extractive species for coastal Integrated Multi-Trophic Aquaculture (IMTA) to recycle the dissolved inorganic nitrogen (DIN) and phosphorus (DIP) wasted by excretive species. To test its suitability, saline aquaculture effluents were simulated in the laboratory using a hydroponics approach to cultivate the plants. Nutrient extraction efficiency, growth performance and nutritional profile were assessed under a range of DIN and DIP concentrations representing three different aquaculture intensification regimes and using Hoagland's solution as a control. Over a 10-week period, hydroponic units under non-limited N and P conditions displayed daily extraction rates between 1.5 and 2.8 mg DIN-N L-1 day-1 and 0.1-0.2 mg DIP-P L-1 day-1 and yielded between 63.0 and 73.0 g m-2 day-1 of H. portulacoides biomass. Relatively to biomass produced, H. portulacoides extracted between 2.6 and 4.2 mg DIN-N g-1 and 0.1-0.4 mg DIP-P g-1. The treatment with low-input of DIN and DIP (6.4 mg N L-1 and 0.7 mg P L-1) induced some degree of nutrient limitation, as suggested by the extremely high extraction efficiencies of DIN extraction (99%) in parallel with lower productivity. The nutritional profile of H. portulacoides leaves is comparable to that of other edible halophytes and leafy greens and could be a low-sodium alternative to salt in its lyophilized form. From the present study, we conclude that the edible halophyte H. portulacoides can be highly productive in hydroponics using saline water irrigation with non-limiting concentrations of DIN and DIP and is, therefore, a suitable extractive species for coastal IMTA in brackish waters.

Nutrient availability affects the polar lipidome of Halimione portulacoides leaves cultured in hydroponics.

Halophytes are increasingly regarded as suitable extractive species and co-products for coastal Integrated Multi-Trophic Aquaculture (IMTA) and studying their lipidome is a valid means towards their economic valorization. Halimione portulacoides (L.) Aellen edible leaves are rich in functional lipids with nutraceutical and pharmaceutical relevance and the present study aimed to investigate the extent to which its lipidome remains unchanged under a range of dissolved inorganic nitrogen (N) and phosphorus (P) concentrations typical of aquaculture effluents. Lipidomics analysis, done by hydrophilic interaction liquid chromatography coupled to high resolution mass spectrometry, identified 175 lipid species in the lipid extract of leaves: 140 phospholipids (PLs) and 35 glycolipids (GLs). Plants irrigated with a saline solution with 20-100 mg DIN-N L-1 and 3-15.5 mg DIP-P L-1 under a 1-week hydraulic retention time displayed a relatively stable lipidome. At lower concentrations (6 mg DIN-N L-1 and 0.8 mg DIP-P L-1), plants exhibited less PLs and GLs per unit of leaves dry weight and the GLs fraction of the lipidome changed significantly. This study reveals the importance of analyzing the lipidomic profile of halophytes under different nutritional regimens in order to establish nutrient-limitation thresholds and assure production conditions that deliver a final product with a consistent lipid profile.

Dietary Mannan Oligosaccharides: Counteracting the Side Effects of Soybean Meal Oil Inclusion on European Sea Bass (Dicentrarchus labrax) Gut Health and Skin Mucosa Mucus Production?

The main objective of this study was to assess the effects of 4 g kg(-1) dietary mannan oligosaccharides (MOS) inclusion in soybean oil (SBO)- and fish oil (FO)-based diets on the gut health and skin mucosa mucus production of European sea bass juveniles after 8 weeks of feeding. Dietary MOS, regardless of the oil source, promoted growth. The intestinal somatic index was not affected, however dietary SBO reduced the intestinal fold length, while dietary MOS increased it. The dietary oil source fed produced changes on the posterior intestine fatty acid profiles irrespective of MOS dietary supplementation. SBO down-regulated the gene expression of TCRß, COX2, IL-1ß, TNFα, IL-8, IL-6, IL-10, TGFß, and Ig and up-regulated MHCII. MOS supplementation up-regulated the expression of MHCI, CD4, COX2, TNFα, and Ig when included in FO-based diets. However, there was a minor up-regulating effect on these genes when MOS was supplemented in the SBO-based diet. Both dietary oil sources and MOS affected mean mucous cell areas within the posterior gut, however the addition of MOS to a SBO diet increased the mucous cell size over the values shown in FO fed fish. Dietary SBO also trends to reduce mucous cell density in the anterior gut relative to FO, suggesting a lower overall mucosal secretion. There are no effects of dietary oil or MOS in the skin mucosal patterns. Complete replacement of FO by SBO, modified the gut fatty acid profile, altered posterior gut-associated immune system (GALT)-related gene expression and gut mucous cells patterns, induced shorter intestinal folds and tended to reduce European sea bass growth. However, when combined with MOS, the harmful effects of SBO appear to be partially balanced by moderating the down-regulation of certain GALT-related genes involved in the functioning of gut mucous barrier and increasing posterior gut mucous cell diffusion rates, thus helping to preserve immune homeostasis. This denotes the importance of a balanced dietary n-3/n-6 ratio for an appropriate GALT-immune response against MOS in European sea bass juveniles.